Electric clock.



Patented Sept. 2, I902. A. F. POOLE.

ELECTRIC CLOCK.

(Application filed Sept. 7, 1901.)

9 Sheets-Sheet (No Model.)

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No. 708,253. Patented Sept. 2, I902.

A. F. POOLE.

ELECTRIC CLOCK.

(Application filed Sept. 7. 1901.) (No Model.)

9 Sheetr-Sheet 2.

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'No. 703,253. Patented Sept. 2', I902. A. F. POOLE.

ELECTRIC CLOCK.

(Application filed Sept. 7, 1901.)

9 Sheets-Sheet 3.

(No Model.)

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No. 708,253. Patentad Sept. 2, 1902.

A. F. POOLE.

ELECTRIC CLOCK.

(Application flliad Sept. 7. 1901.)

9 Sheets-Shea! 4.

(No Model.)

Patented Sept. 2, I902. A. F. POOLE. ELECTRIC CLOCK.

(Application filed Sept 7. 1901.)

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(No Model.)

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No. 708,253. Patented Sept. 2, mm.

A. F. POOLE.

ELECTRIC CLOCK.

App1ication filed. Sept. 7, 1901.)

(No Model.) 9 Sheets-$heet 6.

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No. 708,253. Patented Sept. 2, I902.

A. F. POOLE.

ELECTRIC CLOCK.

"Application filed. Sept. 7, 1901.)

(No Model.) 9 Sheets-Sheet 7.

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No. 708,253. Patented Sept. 2, I902. A. F. POOLE.

ELECTRIC CLOCK.

(Application filed Sept. 7, 1901.)

- (No Model.) 9 Sheets-Sheet 8.

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A. F. POOLE.

ELECTRIC CLOCK.

(Application filed Sept. 7. 1901.) (No Model.)

9 Sheets-Sheet 9.

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UNITED STATES PATENT OEEioE.

ARTHUR F. POOLE, OF \VHEELING, WEST VIRGINIA.

ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 708,253, dated September 2, 1902. Application filed September '7, 1901. Serial No. 74,653. (No model.)

To all whom it may concern:

Be it known that I, ARTHUR F. POOLE, of WVheeling. in the county of Ohio and State of West Virginia, have invented a new and useful Electric Clock, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a front elevation of a masterclock constructed in accordance with my invention, the parts being in their normal position. Fig. 2 is a similar view to Fig. 1 looking in the opposite direction and showing the parts in a different position. Fig. 3 is a front elevation of the synchronizer which I employ. Fig. 4 is a similar view showing the top plate removed, the parts being shown in full lines in the same position as that illustrated in Fig. 3 and in dotted lines showing the parts in the second position of the synchronizer, as illustrated in Fig. 2. Fig. 5 is a side elevation of the left-hand side of the synchronizer. Fig. 6 is a view similar to Fig. 4, showing the parts in the third position just previous to their return to the normal position shown in Figs. 1, 3, and 4. Fig. 7 shows a diagram of the electrical circuits of the master-clock and the secondary clocks, the parts being shown in their normal position. Fig. 8 is a view similar to Fig. 7, showing the synchronizerswitches in full lines corresponding to Fig. 2 and the dotted position of Fig. 4 and in dotted lines to the third position, as shown in Fig. 6. Fig. 9 is a front elevation, on a larger scale, showing a preferred form of secondary clock. Fig. 10 is a side elevation of' the same, and Fig. 11 is a detail sectional view showing the gearing of the center shaft.

My invention relates to the class of electric clocks wherein the master-clock through a series of electrical connections actuates the secondary clocks and is designed to provide means for sending out suitable impulses to the secondary clocks, so as to bring them into synchronism with the master-clock, and also to send out impulses which may be used for actuating the striking mechanism of the secondary clocks as well as to set them up.

Another object of my invention is to pro vide a master-clock which when it is synchronized from a primary clock will itself synchronize the group of secondary clocks driven by it.

Tothat end my invention consists of a master-clock provided with means for sending out impulses, which I have shown in the present case to be at intervals of one minute, and mechanism for setting these parts again in their normal position, and a synchronizer controlled preferably byacam rigidly secured to the minute-hand arbor of the clock, the synchronizer being provided with means for controlling the direction and intensity of the impulses sent out at predetermined periods.

My invention further consists in employing secondary clocks which are provided with polarized detents which control the advance of the hands and, further, in providing striking mechanism for said secondary clocks which is unaffected by the normal impulses sent out by the master-clock, but which is affected by the impulses of greater intensity. The impulses which operate the striking mechanism are a whole or a part of a series of impulses sent out in quick succession between two consecutive normal impulses, preferably just before the next succeeding hour, so that slow clocks are advanced the number of impulses sent out until brought into synchrony with the master-clock.

It also consists in the construction and arrangement of the parts as hereinafter more fully described, and set forth in the claims.

In the drawings, 2 represents an ordinary clock-train, which may be driven in any suitable manner and forms of driving mechanism of a master-clock.

3 is the seconds-hand arbor. Upon this arbor are frictionally mounted two cams 4 and 5, the latter being shown in dotted lines. These cams are rigidly connected together, so that the movement of the heart-shaped cam 5 will move the cam 4.

Mounted upon the frame of the master-clock is an angular lever 6, pivoted at? andhaving an arm 8 provided with a pin 9, adapted to be engaged by the cam 4on the seconds-hand arbor 3. The other arm 10 of the lever 6 is preferably weighted, so as to hold the lever in the desired position for engagement with the cam 4. Projecting from the weighted arm 10 are stop-pins 11 and 12, which are so arranged as to engage in succession a pin 13 on ICO one arm of the bell-crank lever 14, pivoted at to the frame of the clock. A weighted arm 16 tends to make the bell-crank lever 14 drop when the pin 13 is released from engagement with either of the pins 11 or 12.

A short lever-arm 17 has a stud or pin 18, to which is secured a link 19, whichis secured at its opposite end to a stud or pin on the crank-arm 21, secured toarock-shaft 22. This rock-shaft is provided with a projecting arm 23, which is adapted to engage a corresponding arm 24 on a rock-shaft 25, to which is secured a detent 26. A slight space or gap is left between the arms 23 and 24, so that when the pin 13 is released from-the pin 11 and falls into engagement with the pin 12 the detent 26 is not released from its engagement of the segmental rack 27, mounted on the rock-shaft 28 ofthe repeating-switch 29. This repeating-switch 29 is similar to that shown in my eopending application, Serial No. 38,915, filed December 6, 1900.

Upon the rock-shaft 28 is mounted a liquidswitch 30, provided with terminals 31 and 32, one of which is normally out of contact with the liquid in the tube, as shown in Figs. 1 and 7. On the opposite end of the rock-shaft 28 is mounted an armature 33, arranged to vibrate between the poles of the electromagnet 34, these electromagnets beingin the same electrical circuit as the switch. When the detent 26 is released, the tube swings by gravity into a position more nearlyhorizontal under theintiuence of theweighted arm 35, and the liquid then flows overboth terminals and closes the circuit. The current then passes through the electromagnets 34 and acts upon the armature 33 and causes the same to return toils original position, when the circuit is again broken, and so long as the detent 26 is held out of engagement with the segmental rack 27 the vibration of the repeatingswitch will be continued and one impulse after another will be sent out under the normal operation of the repeating-switch, as the detent- 26 isoperated by gravity and engages the toothed segment 27 and remains in this position until again tripped by the mechanism just described. The mechanism by which the repeating-switch is setin motion is reset in normal position by means of an arm 36, mounted on a rock-shaft 37, to which is rigidly attached an armature 38, actuated by electromagnets 39, which arein the same circuit as the repeating-switch 29, and the circuit through these magnets is closed by the liquid-switch 30. This closing of the circuit causes the armature to be moved by the magnets so that the arm 36 is raised, and a pin 40 on the arm 36 is brought into engagement with the arm 16 of the bell-crank lever 14, and thereby lifts the bell-crank so that the pin 13 is brought into the position to engage the pin 11 as soon as the circuit is broken and the arm 36 has dropped away from the bellcrank 14. I will now describe the operation of this part of my device used in sending on an impulse every minute.

As the seconds-hand arbor revolves the cam 4 is brought into contact with the pin 9 on the arm 8 of the lever 6 and by contact with the said pin 9 depresses the arm 8 and lifts the weighted arm 10 gradually, so that the pin 11 is lifted out of engagement with pin 13 on the bell-crank 14, and by reason of the weight of the arm 16 of the bell-crank 14 the pin 13 is brought into engagement with the pin 12 on the arm 10 on the lever 6. This movement through the connection of the bell-crank 14, the arm 17, link 19, and crankarm 21 on the rock-shaft 22 brings the arm 23 into contact with the arm 24, secured to the rock-shat t 25, which carries the detent 26 without tripping the same. As the secondshand arbor further revolves the arm 8 is released,and the pin 12 drops outofengagement with the pin 13 on the bell-crank lever 14,which then falls by gravity until the weighted arm 16 engages the pin 40 on the lever 36, which rests on a suitable backing-pin, and this movement of the bell-crank causes the arm 17 through the connecting-link 19 to'lift the crank-arm 21 upon the rock-shaft 22, thereby causing the arm 23 to engage the arm 24 on the rockshaft 25in such a manner as to release the de tent 26 from engagement with toothed segment 27 of the repeating-switch. The switch upon being released swings by gravity, as previously described. The circuit is then closed in the liquid-switch 30 and energizes the magnets of the repeating-switch and the magnets 39 of the restoring device. ergizing of the magnets causes the armature to move, so that the liquid-switch is again brought into its normal position, and the arm 36, carrying the pin 40, is raised, and by means of this pin 40 the bell-crank lever is raised to its normal position, the lever 6 having been previously brought into this normal position as the pin 9 left its engagement with the cam 4 and left it in the proper position to engage the pin 13, as shown. This movement of the bell-crank through the connections described brings the detent 26 into proper position to engage the toothed segment, and thus retain the repeating-switch in its normal tilted position.

On the minute-hand arbor of the clockframe is frictionally mounted a sleeve, which carries a cam 41, having a high and low surface 42 and 43. Upon the sleeve carrying the cam 41 is a second cam 44, the function of which I will hereinafter describe. At a suitable point upon the frame of the clock a bent lever 45 is pivoted at 46 and has an arm 47, provided with a pin 48, adapted to engage the cam-surfaces 42 and 43 of the cam 41. The weighted arm 49 of this bent lever is provided with pins 50 and 51, adapted to engage pin 52 on the arm 50 of the bell-crank lever 54, which is pivoted at 55 of the frame of the clock. To the weighted arm 56 of the bell- This encrank 54 a link 57 is connected at its upper end and at its lower end to a tripping-lever 58, by which the liquid-switches of the synchronizer are released. The sychronizer comprises a suitable frame having an outer plate 60, to which are secured a requisite number of binding-posts, and an inner plate 61, suitably spaced from the front plate 60 by post 62. Between these plates I mount the tripping mechanism and the resetting mechanism.

On a shaft 63 is mounted a double catch having arms 64: and 65, the arm 64 being adapted to engage an arm 66 on the shaft 67, upon which is mounted a two-way liquidswitch 68, having terminals a, b, and c, the shaft 67 being so counterweighted that when the arm 66 is released the tube will assume the position as shown in Fig. 8. The shaft 67 is also provided with a finger 69, which is adapted to engage with the pivoted dog 70, pivoted on the arm 71 at the point 72. This pivoted dog is normally held out of engagement with the finger 69 by a pin 73, secured to the plate 61. This pin also acts as a stop to limit the movement of the lever 71, the lever being secured to the shaft 74:, which has secured thereto an armature 75, actuated by electromagnets 76 in one direction and by a retractile spring '77 in the opposite direction. The shaft 63 is provided with an arm 63, which is adapted to be engaged by adjustable pin 58 on the lever 58. The shaft 63 is also provided with a pin 78, adapted to receive the tension-spring 79, which is connected at its other end to pin 80 on shaft 81. This shaft 81 has an arm 82, which engages an arm 83, which projects from the shaft 84, this shaft being provided with a finger 85, which is engaged by a pivoted dog 86, provided with a weighted arm 87 and a tail 88, which engages a stop 89, projecting from the rear of the front plate 60, as shown in Fig. 3. The dog 86 is carried upon an arm 90, which is rigidly secured to a shaft 91, which is provided with an armature 92, which is actuated by electromagnets 93 in one direction and by the spring 77 in the opposite direction. Upon the shaft 91 is secured an arm 94, to which is pivoted a gravity-pawl 95, which engages a ratchet-wheel 96, provided withseventy-eight teeth. The feeding action of the pawl is limited by a stop-pin 97, so that the wheel 96 is advanced one tooth at a time, a suitable detent preventing any retrograde movement.

Upon the shaft 99,which carries the toothed wheel 96, is secured a disk 100, provided with notches 101, located at intervals in its periphery, the spaces between the notches being progressively greater from one to twelve, corresponding with the hours. Upon a shaft 102 is secured an arm 103, adapted to engage the pivoted dog 86 when the finger 104: is moved from the lowest point of the notch outwardly upon the periphery of the disk 100. Upon the shaft 84 is mounted adouble-path liquid-switch 105, similar to the switch 68 and having terminals (1, e, and/i The shaft 84; is also provided with a counterweight 106, which tilts the tube downwardly when the detent arm 83 is released. Its downward movement is limited by a suitable stop-pin, as is also the movement of the arm 82. The tripping-lever 58 is connected to the ratchetfeed mechanism by a link 59,provided at its lower end with a slot 59, which moves on a pin 90', secured to an arm 94 upon the shaft 91, so that the train of mechanismby which the synchronizer is released by the masterclock is restored to its normal position on the first stroke of the armature 92, actuated by the electromagnets 98.

I will now describe the electrical connections which I employ. I

In the master-clock I use three circuits during three distinct periods of the hour. The one used during the first period of the hour to send out currents of normal intensity in one direction is that shown in Fig. 7. Starting at the plus pole of battery A the current passes to binding-post 107, thence to the electrode a of the liquid-switch 68, through the liquid to the terminal I) of said switch, thence to binding-post 108, to binding-post 109, then through the secondary-clock circuit, this circuit returning to the master-clock at bindingpost 110, thence to binding-post 111, which is a terminal of one of the coils on one leg of the magnet 34:, which actuates the repeatingswitch 29. In this switch the current passes to binding-post 112, thence to electrode 31 of the electric switch 30, which when the switch is in operation will close the circuit through the liquid-switch, as shown in dotted lines, the liquid connecting the terminal 31 and the terminal 32. The current passes thence to binding-post 113, then to binding-post 114, from which it is carried to terminal (2 of the liquid-switch 105, thence through the conductingliquid to the terminal d, thence to the binding-post 116, then through the other coil 3a of the repeating-switch 29, thence to bindingpost 117, then to binding-post 118, then passes through magnet 76,controlling the switch 68 of the synchronizer, thence to binding-post 119, then to binding-post 120, from which itis carried through the restoring-magnet 39 of the minute-release to binding-post 121,and thence to the plus pole of battery B,and then to the minus pole of battery A. It will be observed that when the path of the circuit is as just described the magnets 93, which control the switch 105 and the battery B, are cut out of the circuit. The circuit used during the second period of the hour to send out impulses of normal intensity in the reverse direction of that just described is illustrated in Fig. 8. Starting from the plus pole. of battery B the current passes to binding post 121, then through the magnet 39 of the minute-release to the binding-post 120, thence to bindingpost 119, which is connected to magnet 76 and the synchronizer, which magnet controls liquid-switch 68. From the magnet 76 the current passes from the binding-post 118, thence to binding-post 117, and then through the coil on one leg of the magnet 34 of the repeating-switch 29, thence to binding-posts 116, then to binding-post 115, from which it passes to terminal (Z of the liquid-switch 105, thence through the conducting liquid of said switch to terminal 6, to binding-post 114,

thence to binding-post 113, then to terminal 32 of the liquid-switch 30 of the repeating-' switch, through the conducting liquid to the terminal 31, thence to binding-post 112, then through the other leg of the magnet 34, thence to the binding-post 111, then to binding-post 110, from which it passes through the secondary-clock circuit and enters the master clock at binding-post 109, thence to bindingpost 108, to the terminal b of the liquidswitch 68, through the liquid of said switch to the terminal 0, thence to binding-post 122,

then to the minus pole of battery 79. In this case the circuit is the sameas that described during the first period, except that the impulses are sent out in the reverse direction from those of the first period, and battery A' and magnets 93, which restore the switch 105, are inoperative. During the third period of the hour, which is very short relative to the two periodsjust described,impulses of greater intensity are sent out in quick succession and in the same direction as those sent out during the second period of the hour. Starting at the plus pole of battery A, the current passes through binding-post 107 to binding-post 123, thence to the magnets 93, thence to bindingpost 124, thence to binding-post 125, thence to the terminalfof the switch 105, as shown in dotted lines, thence through the liquid of said switch to terminal 6, thence to binding-pest 114, thence to binding-post 113, thence to terminal 32 of liquid-switch 30 of the repeatingswitch 29, through the liquid-switch to terminal 31, thence to binding-post 112, from which it is carried to one leg of the magnet 34, then to binding post 111, thence to binding-post 110, from which point it goes through the secondary-clock circuit and again enters the master-clock at binding-post 109, thence to binding-post 108, then to terminal I) of the liquidswiteh 68 of the synchronizer, through the liquid to terminal 0, thence to binding-post 122, the minus pole of battery B, through the minus pole to the plus pole of battery B, and then to the minus pole of battery A. In this case the impulses are of double the intensity of those sent out during the first two periods of the hour, as both batteries A and B are connected. During this period the following portions of the circuit employed during the first two periods are cutout: magnet 76, which controls the switch 68 of the synchronizer, magnet 39 of the restorer for the minute-release, and one leg of the magnet 34, which operates the repeating-switch 29.

I will now describe the operation of the syn chronizer which I employ,which performs two very important functions, viz: changing the direction of the impulses which are sent out by the master-clock during the first two periods of the hour and the sending out of impulses of double intensity and in quick succession during the third period of the hour. It will be noted that the synchronizer does not in itself make and break the circuit; but the switches 68 and 105 when changed from their normal position by the mechanism which I am about to describe alter the path of the current when the circuit is closed by the repeating-switch in the manner already described. As illustrated in the drawings, Figs. 1 and 2, the position of the high and low parts of the cam 41 determines the position of the switches, and consequently the kind of current which will be sent out by the masterclock. When the parts are in the position shown in Fig. 1, the pin 48 being on the low part 42 of the cam 41, the lever 45 is held in such a position that the pin 50 on the arm 49 of said lever engages the pin 52 on the bellcrank lever 54, and thus prevents the lever 54 from falling. The weighted arm 56 of this lever is connected by a link 57 to a trippinglever 58, having an adjustable pin 58, which in the positions shown in Figs. 1, 3, and 4 is held out of contact with the arm 63, which operates the switch-holding catch 64, and the arm 82, which acts as a detent to the arm 83, which is on the axis of the switch 105. When the cam rotates during the first period of the hour and the parts are in the position just described, the repeating-switch is released once a minute, and since the detent 26 is restored by the magnet 39 in the manner previously described but a single impulse is sent out for each revolution of the seconds-hand cam 4. Then the incline 41, leading to the high part of the cam 41, reaches the pin 48, the arm 47 is depressed, as shown in Fig. 2, and the pin 50 on the weighted arm 49 of lever 45 is raised so that the pin 52 on the arm 53 of bell-crank lever 54is released and falls until it engages the pin 51 on the arm 49. This movement, by means of the link 57, connected to the tripping-lever 58, depresses said lever so that the adjustable stop 58 comes in contact with the arm 63' on the shaft 63 and depresses it, thereby moving the catch 64 so as to unlock the arm 66 upon the shaft 67, which forms the axis of the liquid-switch 68, thus allowing the counterweight 67 to tip the switch 68 into the position shown in Fig. 8. This release of the switch 68 occurs between two consecutive impulses, so that after the switch 68 has been tipped downwardly by the counterweight the nextimpulse will be sent out by the masterclock through the new path made by the switch 68, as described in the circuit of the second period namely, in the reverse direction to that of the first period. The catch 65, which is perated at the same time that the catch 64 releases the switeh 68, moves into the path of the pin 71 on the arm 71, which is secured to the shaft 74, which carries the armature 75 of the magnet '76, by which the switch 68 is restored to normal position, as I shall hereinafterdescribe. During this period the impulses are sent out once a minute, but in the reverse direction, by the repeating-switch. As the cam 41 continuously revolves the pin 48 drops from the high part 43 of the cam to the low part 42, and in so doing the weighted arm a0 of the lever 45 drops, thus releasing the arm 53, which falls still further under the action of the weighted arm 56, and by its connection to the tripping-arm 5S and the adjustable pin 58 still further depresses the arm 63 on the shaft 63 and causes said arm to engage the tail of the detent 82 on the shaft 81, thus tipping said detent into the position shown in full lines in Fig. 6. This movement of the detent releases the arm 83, which holds the switch 105 against the action of its counterweight 106 and allows the switch to tip under the action of the counterweight so as to establish a new path for the current, as shown in dotted lines in Fig. 8. This change of the switch also occurs between two consecutive impulses sent out by the repeating-switch, and when the switch 105 is thus tipped currents or impulses of double the intensity of those previously sent out and in the same direction of those of the next preceding period are sent out the next time the repeating-switch is tripped by the seconds-hand cam, since the restorer-magnets 30 are cut out of the circuit, thus preventing the detent 26 from engaging the toothed segment 27 of the repeating-switch, and so long as the switch 105 remains in the tipped position the repeating-switch will continue to send out impulses of double intensity and in quick succession until the switch 105 is again restored to its normal position, as shown in full lines in Fig. 8. This restoration is accomplished in the following manner: Before the tube 105 is restored to its normal position the magnets 93, which are now in circuit, cause the armature 92 to vibrate for each currentsent out by the repeating-switch, and with each vibration the toothed wheel 96 will be fed by the pawl 95 one tooth by the vibration of the armature. The disk 100, which is mounted upon the shaft 99, to which the toothed wheel 96 is also secured, is provided on its face with notches which are somewhat similar to the locking-plate of an ordinary striking-clock. If the finger 104, mounted upon shaft 102, be in the position shown in Fig. 3 and the tubes and the switches 68 and 105 be in the position shown in dotted will not be returned to its normal position. 0n the first forward stroke of the armature 02 the releasing mechanism of the syncl1ronizer, through the link connection previously described, restores this portion of the mechanism into its normal position, without, however, accomplishing the resetting of the switches 68 and 105. In the case just supposed the disk 100 will permit the armature 02 to make three strokes before resetting the switch 105, for the reason that the magnets 39 of the restorcr of the minute-release are cut out of the circuit and the detent 26 of the repeating-switch is held out of engagement with the toothed segment 27, and said switch will be permitted to vibrate as long as the detent is held out of engagement. The third period is ended by the restoration of the switch 105 to its normal position upon the back stroke next succeeding the three forward feeding strokes in the case just described. As soon as the switch 105 is restored to its normal position by the back stroke of the armature 92 an impulse is sent out, since the repeating-switch has not yet stopped. Said impulse will pass through the same path as that of the second period of the hour, and the restoringmagnet 30 being again in circuit the arm 36, controlled thereby, will lift the releasing mechanism of the minute-release, and thereby restore the detent 26 to a position to engage the toothed segment 27, and thus stop the repeating-switch from sending out any more impulses. During this last impulse sent out by the repeating-switch the magnets 76, which control the armature 75, which acts to restore the switch 68 to its normal position, accomplishes this movement upon the back stroke of the armature, since the arm 71, actuated by the armature '75, is free to move because of the fact that the catch 65 has been restored to its normal position out of the path of the pin '71 on the first stroke of the armature 92 of the third period of the hour, and the first movement of the armature 75 during the sending out of the impulse immediately succeeding the third period of the hour is drawn into the position shown in dotted lines in Fig. 4, and the pawl 70, mounted thereon, being freed from the stop-pin 73 and actuated by the spring will be brought into the position shown in dotted lines, so that its end will engage the finger 69 upon the shaft 67, which is the axis of the switch 68, upon' the next back stroke of the armature '75, thereby restoring the switch to its normal position, where it is again held by the catch 6%, which engages the arm 66 upon its axis 67. This completes the cycle of operation.

It will be obvious from the foregoing description that d uring the firstthirty minutes of the hour, the cycle starting at the first minute of the hour, impulses of normal intensity will be sent out once a minute in one direction, this constituting the first period of the hour. Then the switch 68 of the synchronizer being periods of the hour.

dropped will establish a path for the current, so that the repeating-switch will send out impulses once a minute for the remainder of the hour and with the same intensity as those of the first period, but in the opposite direction, until the end of the fifty-ninth minute of the hour, at which time the switch 105 is dropped, and upon the next succeeding release of the repeating-switch by the'secondshand cam impulses of double intensity, but in the same direction as those in period two, will be sent out by the repeating-switch. The number of these currents depends upon the condition of the disk 100 and will vary from one to twelve in the clock arranged as shown. On the last back stroke of the armature 92 the switch 105 is restored. This constitutes the third period of the hour, and during this period the secondary clocks which are slow are set up and if' provided with striking mechanism will strike the hour to correspond to the number of currents sent out during this period. A restoring-current which belongs neither to the first, second, or third periods, but which goes over the same path as the second period of the hour and of a duration of but a single impulse, is sent out immediately after the conclusion of the third period and before the beginning of the first. This impulse restores the switch 68 to its normal position and establishes a normal path for the first impulse of the new hour. This completes the cycle of the impulses sent out during the hour.

The type of secondary clock which I employ is diagrammatically shown in Fig. 7 and is provided with an electrical driving mechanism 126 of any suitable construction. A toothed wheel 127, with sixty teeth thereon, is secured to the arbor which carries the minute-hand, and this wheel is provided with pin 128, which is adapted to be engaged by a polarized detent 129, which is held in a position not to engage the pin during the first period of the hour, but which will be pulled over into the position to engage the pin (shown by dotted lines in Fig. 8) during the second and third periods of the hour, since the impulses of these periods are sent out in the reverse direction from those of the first period, and any slow clocks will be advanced toward twelve one minute for each impulse of the third period of the hour. The clocks which are correct will have the detent in engagement with the pins on the minute-hand wheel, and the detent will prevent these clocks from being aitected by these impulses. Upon the first impulse of the first period of the new hour the detents 128 will be thrown out of engagement and the minute-hand of the secondary clock will be advanced one minute at a time at each impulse sent out by the repeating-switch during the first two As shown in Fig. 7, I

have provided the secondary clock with a single-stroke electric bell and on the same circuit as the secondary clock.

This magnet roaess may be in series or in parallel with the main actuating-magnet of the secondary clock, as best suits the particular case where these clocks are employed. This bell is so adjusted that it is not afiected by the currents of normal intensity sent out by the repeatingswitch of the master-clock during periods one and two, but is actuated by the currents of double intensity of the third period.

From the foregoing description it will be apparent that the secondary clocks are each hour brought into synchronism with the master-clock. The exact time is determined by the position of the cam 41 on the minute-hand of the master-clock,and the high and lowparts of this cam determine when these three periods shall begin. It is obvious that by altering the position of the cam 41that is, by turning it forward or backthe secondary clocks will be brought into synchronism with it at the beginning of the next succeeding third period, so that all that is necessary in order to set the secondary clocks on the circuit forward or back is to turn the cam 41 on the minute-hand arbor of the master-clock the desired number of minutes, when upon the next following third period the secondary clocks will be brought into synchronism with the master-clock. This change of position may be made by hand or may be accomplished by any suitable means for synchronizing selfdriven clocks, one form of which is shown in dotted lines in Fig. 1, in which a circuit-closer 130 closes the circuit through the magnet 131, which actuates the armature 132, attached to a lever 133, provided with two branches 134 and 135,provided with suitable rollers at their ends adapted to engage the cams 5 and 44 on the seconds hand arbor and minute hand arbor, respectively, so that when magnet 131 is energized the seconds-hand is brought to and the minute-hand is brought to some predetermined point by the clock which controls the circuit-closer 130. As this method is well known in the art, further description of this part of the system is unnecessary.

In Figs. 9, 10, and 11 I illustrate the preferred form of my secondary clock in more detailed views. As shown in these figures, the electrical driving mechanism consists of an electromagnet 136,having its armature 137 pivoted on a lever 138, having a counterweighted arm 139. The lever 138 is pivoted at 140, and the upper arm of this lever carries a pivoted pawl 141, engaging the teeth of the main wheel 127. A retainingdetent 142 also engages the teeth of wheel 127, this preventing backward rotation of the wheel when the pawl 141 is moved back to engage the next tooth. The polarized detent 129 is pivoted to a brass strip 143, secured to the front and shorter leg of a permanent horseshoe magnet 144. The detent swings between pole-pieces 145, secured to the opposite poles of an electromagnet 146, and the hooked end of the detent is in position to engage the pin 128 when the parts are in the position shown in Fig. 9, this being the position during the second half-hour. The operation of these parts is as set forth in the previous description of the secondary clock. The electric drivinginechanism, consisting of the magnet and counterweighted armature-lever, moves the wheel 127 through the pawl l ll and through the connectedgearing of usual form the hands of the clock are actuated.

The advantages of my synchronizing system are many, since by its use I am enabled to employ secondary clocks of the step-bystep type which are synchronized every hour automatically by a mastenclock which sends out impulses to accomplish this result. The master-clock which I employ is so constructed as to drive the secondary clocks, synchronize them, and when provided with a single stroke electric hell I am enabled to strike the hour on the secondary clock without the addition of extra mechanism to the secondary clock, also to set them up, and I am enabled to accomplish all these results with a single circuit. The synchronizing of secondary clocks of the step-by-step type when automatically controlled by a master-clock, such as shown, renders these secondary clocks reliable, since it is at once apparent whether the clock is'operating properly, because of the fact that the clock is either stopped because of some derangement or broken connection with the master-clock. If properly connected, the secondary clock operates in the usual manner and is sure to be correct, since it is synchronized automatically once each hourby the master-clock. By providing the secondary clocks with a circuit which is made and broken only by the master-clock and then synchronizing the clocks over this circuit it is impossible for the secondary clocks to fail because of imperfect contacts in them, which have heretofore been employed. Another advantage is that by eniploying the master-clock ot' the type shown, in which the synchronizer which controls the secondary clock is controlled by a cam rigid with the minute-hand, the setting of this cam or minute-hand forward or back will at the next synchronizing period set the secondary clocks forward or back the same amount, and this movement of the cam may be accomplished either by hand or by connecting the synchronizing circuit-breaker 130 with an observatory-signal. Hence a signal sent from the observatory will first synchronize the master-clock, and then the master-clock at its next ensuing synchronizing period will synchronize the secondary clocks on the circuit. So far as I am aware this has never been accomplished heretofore, nor has it been possible heretofore to automatically synchronize secondary clocks of the step-by-step type on a single circuit. While I have described the extra impulses by which the sec-.

ondary clocks are set up as being of double intensity, it is obvious that this need not be so, as impulses of normal intensity will serve equally well and accomplish this purpose.

Many changes may be made in the form and arrangementof the parts by those skilled in the art, since lVhat I claim is 1. In a synchronized clock system, a series of secondary clocks, a master-clock having connections arranged to give electric impulses to them at determined intervals and fora determined period in one direction, and mechanism for sending out impluses for another period at determined intervals in the opposite direction; substantially as described.

2. In a synchronized clock system, a series of secondary clocks, a master-clock having connections arranged to give electric impulses to them at determined intervalsin one direction, and for a predetermined period, and in the opposite direction at determined intervals and for a predetermined period, followed by a series of impulses in quick succession and in the same direction as the last preceding period, whereby the secondary clocks are synchronized; substantially as described.

In a synchronized clock system, a master-clock having connection with a series of secondary clocks arranged to give electric im pulses to them at determined intervals in one direction and for a predetermined period, and in the opposite direction at determined intervals and for a predetermined period, followed by a series of impulses ofaugmented intensity in quick succession and in the same direction as the last preceding period, whereby the secondary clocks are synchronized; substantially as described.

4. In an electric clock, a switch normally locked, releasing mechanism adapted to unlock said switch soas to make and break the circuit at predetermined intervals; mechanism adapted to restore the releasing mechanism to its normal position, in which said switch is locked, said restoring mechanism beingin the same circuit with said switch; substantially as described.

5. In an electric clock, a switch adapted to send out impulses at predetermined periods, releasing mechanism operated by the clockmovement adapted to unlock said switch at said predetermined interval, secondary clocks adapted to receive impulses sent out by said switch, mechanism adapted to restore the releasing mechanism to its normal position, in

which said switch is locked and the circuit is broken, said restoring mechanism being in the same circuit with said switch and secondary clocks; substantially as described.

0'. In an electric clock having aswitch adapted to send out impulses at predetermined intervals, a synchronizer having switches adapted to change the direction of the impulses sent out by said switch; substantially as de scribed.

7. In an electric clock havingaswitch adapted to send out impulses atpredetermined intervals,asynchronizer having switches adapted to change the direction and intensity of the impulses sent out by said switch; substantially as described.

8. An electric clock having a switch adapted to send out impulses at predetermined intervals, a synchronize! having switches adapted to change the direction of said impulses, a cam operated by the clock mechanism and arranged to control the switches of the synchronizer, thereby determining the period during which impulses are sent out in a given direction; substantially as described.

9. In an electric clock havingaswitch'adapt ed to send out impulses at predetermined intervals for predetermined periods and in quick succession for another period relatively short, releasing mechanism controlling said switch, a restorer normally adapted to reset said releasing mechanism and lock said switch after each impulse during the longer periods, a synchronizer having switches adapted to change the direction of the current during the long periods, said restorer being normally in circuit with the switch which sends out impulses at predetermined intervals, but adapted to be cut out of said circuit by one of the switches of the synchronizerduring the relatively short period during which said switch which sends out impulses, so that said switch is permitted to send out a series of impulses in quick succession substantially as described.

10. In an electric clock having a switch adapted to send out impulses at predetermined intervals, a synchronizer having switches adapted to change the direction of the impulses sent out by said switch, releasing mechanism operated by the clock mechanism by which the interval at which said impulses are sent out is determined, a synchronizer having switches adapted to change the direction of said impulses, a cam operated by the clock mechanism arranged to control the switches of the synchronizer, thereby determining the period during which impulses are sent out in a given direct-ion; substantially as described.

11. In an electric clock provided with a switch adapted to send out impulses, a synchronizer having switches arranged to form a portion of a path for said impulses, said synchronizing switches being adapted to change the direction in which said impulses are sent out; electromagnets forming a part of the circuit and adapted to effect the restoration of said switches to their normal position on the back stroke of their armatures; substantially as described.

12. In an electric clock having a switch adapted to send out impulses at predetermined intervals, a synchronizer having switches released in succession, mechanism operated by the clock mechanism by which said release is effected, said switches when released altering the direction in which the impulses are sent out, electromagnets located voaese store them "to their normal position in the revcrse order to which they were released upon the back stroke of the armatures; substantially as described.

13. In an electric clock having a switch adapted to send out impulses at predetermined intervals, a synchronizer having switches released in succession, mechanism operated by the clock mechanism by which said release is effected, said switches when released altering the direction in which the impulses are sent out, electromagnets located in circuit with said switches adapted to restore them to their normal position upon the back stroke of the armatures; substantially as described.

14. In an electric clock having a switch adapted to send out impulses at predetermined intervals released by the clock mechanism, a synchronizer having a switch also released by said clock mechanism, said switch being adapted when released to change the direction without altering the interval at which said impulses are sent out; substantially asdescribed.

15. In an electric clock having a switch adapted to send out impulses at predetermined intervals released by the clock mechanism, a synchronizer having a switch also released bysaid clock mechanism, said switch being adapted when released to change the direction without altering the interval at which said impulses are sent out, and a second switch adapted to be released by said clock mechanism after the firstswitch has been released, whereby the frequency of the impulses sent out is permitted until said switch is returned to its normal position; substantially as described.

16. In an electric clock having a switch adapted to send out impulses at predetermined intervals released by the clock mechanism, a synchronizer having a switch also released by said clock mechanism, said switch being adapted when released to change the direction without altering the interval at which said impulses are sent out, a second switch adapted to be released by said clock mechanism after the first switch has been released, whereby the frequency of the impulses sent out is permitted, and a locking-disk provided with aseries of notches arranged at intervals, an electromagnet in circuit with the impulsesending switch and said second switch of the ICC synchronizer, feeding mechanism actuated by said electromagnets, whereby said lockingdisk is fed step by step, resetting mechanism for said second switch which is held out of operative position during the interval between the notches in said locking-disk, said switch being returned to its normal position when the resetting mechanism again engages the next succeeding notch in the locking-disk; substantially as described.

17. In an electric master-clock having a switch adapted to send out impulses at prein circuit with said switches adapted to re- A determined intervals, a releasing mechanism therefor, a restorer for said switch in circuit therewith, a synchronizer having switches adapted to change the direction and intensity of said impulses, electromagnets having vibrating armatures adapted to restore said switch, resetting mechanism secured to said armatures, clock mechanism adapted to de termine the time at which said change of direction and intensity takes place, releasing mechanism operated by said clock mechanism by which said synchronizer-switches are released in succession, one of said switches altering the direction of the impulses sent out without afiecting the intensity of the current, the second switch of said synchronizer being adapted to increase the intensity of the current without changing its direction, said second switch permitting the repeating-switch to send out impulses of augmented intensity in rapid succession, feeding mechanism actuated by the vibrating armature of one of said electromagnets, releasing mechanism whereby said synchronizing-switches are operated, also actuated thereby, said armature resetting said releasing mechanism for both switches on its first feeding stroke, a locking-disk adapted to be actuated by said feeding mechanism, notches in the periphery of said locking-disk arranged at intervals, resetting mechanism for said second switch adapted to engage the notches and the periphery of said lockingdisk, the space between said notches determining the number of impulses of augmented intensity sent out by the repeating-switch in quick succession, said second switch with the synchronizer being restored to its normal position on the first back stroke of the electromagnet which operates the locking-disk when the resetting mechanism is dropped into registry with the next succeeding notch, the resetting of said switch again completing the circuit through the restorer for the repeatingswitch, and thereby establishing the circuit through the magnet of the synchronizerswitch first released, and thereby actuating its armature and the resetting mechanism secured thereto so that upon the back stroke of the armature, the first-released switch of the synchronizer is returned to its normal position; substantially as described.

18. A synchronized clock system comprising a primary clock having connection with a self-driven master-clock, mechanism by which said master-clock is synchronized therewith, said master-clock having connections with a series of secondary clocks arranged to give electric impulses to them at determined intervals and for determined periods in one direction, and mechanism for sending out impulses for another period and a determined interval in the opposite direction, whereby said secondary clocks are synchronized with said master and primary clock; substantially as described.

In testimony whereof I have hereunto set my hand.

ARTHUR F. POOLE. lVitnesses:

L. A. CoNNER, J r., G. B. BLEMING. 

